[LLDB] Add LoongArch software breakpoint trap opcode

Use `break 0x5` for LoongArch software breakpoint traps.
The magic number 0x5 means `BRK_SSTEPBP` as defined in
the kernel header `asm/break.h` on LoongArch.

Reviewed By: SixWeining, xen0n

Differential Revision: https://reviews.llvm.org/D137519

diff --git a/lldb/source/Host/common/NativeProcessProtocol.cpp b/lldb/source/Host/common/NativeProcessProtocol.cpp
index cdb5984..21f382d 100644 (file)
--- a/lldb/source/Host/common/NativeProcessProtocol.cpp
+++ b/lldb/source/Host/common/NativeProcessProtocol.cpp
@@ -507,6 +507,8 @@ NativeProcessProtocol::GetSoftwareBreakpointTrapOpcode(size_t size_hint) {
   static const uint8_t g_ppcle_opcode[] = {0x08, 0x00, 0xe0, 0x7f}; // trap
   static const uint8_t g_riscv_opcode[] = {0x73, 0x00, 0x10, 0x00}; // ebreak
   static const uint8_t g_riscv_opcode_c[] = {0x02, 0x90};           // c.ebreak
+  static const uint8_t g_loongarch_opcode[] = {0x05, 0x00, 0x2a,
+                                               0x00}; // break 0x5
 
   switch (GetArchitecture().GetMachine()) {
   case llvm::Triple::aarch64:
@@ -541,6 +543,10 @@ NativeProcessProtocol::GetSoftwareBreakpointTrapOpcode(size_t size_hint) {
                           : llvm::makeArrayRef(g_riscv_opcode);
   }
 
+  case llvm::Triple::loongarch32:
+  case llvm::Triple::loongarch64:
+    return llvm::makeArrayRef(g_loongarch_opcode);
+
   default:
     return llvm::createStringError(llvm::inconvertibleErrorCode(),
                                    "CPU type not supported!");
@@ -567,6 +573,8 @@ size_t NativeProcessProtocol::GetSoftwareBreakpointPCOffset() {
   case llvm::Triple::ppc64le:
   case llvm::Triple::riscv32:
   case llvm::Triple::riscv64:
+  case llvm::Triple::loongarch32:
+  case llvm::Triple::loongarch64:
     // On these architectures the PC doesn't get updated for breakpoint hits.
     return 0;
 

diff --git a/lldb/source/Target/Platform.cpp b/lldb/source/Target/Platform.cpp
index 306ee99..7bb2b1c 100644 (file)
--- a/lldb/source/Target/Platform.cpp
+++ b/lldb/source/Target/Platform.cpp
@@ -1939,6 +1939,14 @@ size_t Platform::GetSoftwareBreakpointTrapOpcode(Target &target,
     }
   } break;
 
+  case llvm::Triple::loongarch32:
+  case llvm::Triple::loongarch64: {
+    static const uint8_t g_loongarch_opcode[] = {0x05, 0x00, 0x2a,
+                                                 0x00}; // break 0x5
+    trap_opcode = g_loongarch_opcode;
+    trap_opcode_size = sizeof(g_loongarch_opcode);
+  } break;
+
   default:
     return 0;
   }